JP6940291B2 - Fireproof cable - Google Patents

Description

The present invention relates to a refractory cable having one or more insulated cores.

Conventionally, wiring cables with improved fire resistance (hereinafter referred to as "fire resistant cables") have been proposed for the purpose of maintaining the power supply to fire extinguishing equipment and the like for as long as possible in the event of a fire.

For example, as shown in FIGS. 7A and 7B, one of the conventional fireproof cables (hereinafter referred to as "conventional cable 900") includes a plurality of insulated cores 910 having improved fireproof performance. It includes a tubular sheath 920 that bundles a plurality of insulated wire cores 910, and a tubular sheath 920. More specifically, each of the insulating cores 910 is formed of a conductor core wire 911, a fireproof tape 912 wound around the outer periphery of the conductor core wire 911, and an insulator layer 913 formed so as to cover the fireproof tape 912. There is. Further, the plurality of insulated wire cores 910 thus formed are temporarily fixed together with inclusions 930 by a presser foot tape 940 and then covered with a sheath 920 (see, for example, Patent Document 1).

In the conventional cable 900, the fireproof tape 912 functions as a fireproof layer that protects the conductor core wire 911 in the event of a fire. As shown in FIG. 7C, the refractory tape 912 is formed by attaching a base tape 912a such as a polyethylene film and scales of mica, which is a heat-resistant material (flame-retardant material), to the base tape 912a. It has a mica layer 912b and the like.

Japanese Unexamined Patent Publication No. 2000-207951

In the conventional cable 900, when the fireproof tape 912 is spirally wound around the conductor core wire 911 from the viewpoint of covering the conductor core wire 911 with mica scales as closely as possible to improve the fire resistance performance, the edges of the fireproof tape 912 overlap each other. It is designed to be wrapped while letting it wrap. That is, the refractory tape 912 is laminated and wound.

However, if the conventional cable 900 is bent at the time of manufacturing or arranging the conventional cable 900, a gap may occur in the overlapping portion of the refractory tape 912 due to the displacement or bending of the refractory tape 912. If such a gap exists, the conductor core wire 911 is exposed to the outside through the gap, which may reduce the fire resistance performance of the fireproof cable. In addition, if such a gap is present, the conductive substance may enter the gap, and the insulating property of the conductor core wire 911 may be lowered.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fireproof cable capable of appropriately maintaining fireproof performance even when bent.

In order to achieve the above-mentioned object, the refractory cable according to the present invention is characterized by the following (1) to (2).
(1)
A refractory cable with one or more insulated cores
The insulated wire core is
The refractory layer and the refractory tape are spirally wound so that the conductor core wire and the refractory tape in which the resin layer and the refractory material layer are laminated cover the outer periphery of the conductor core wire while overlapping the edges of the refractory tape. at least one refractory layer provided along the longitudinal direction of the conductor wire so as to cover the outer periphery of the conductor core, and a holding yarn refractory which is wound around the outer circumference of the refractory layer possess,
The refractory layer is composed of scaly mica itself.
The resin layer contains powdered mica, and the resin layer contains powdered mica.
The size of the powdery mica is smaller than the size of the scaly mica.
Must be a fireproof cable.
(2)
In the fireproof cable described in (1) above,
The holding thread
Includes an S-wound wound around the outer circumference of the refractory tape so as to circulate in the S-twist direction, and a Z-wound wound around the outer circumference of the refractory tape so as to circulate in the Z-twist direction.
Must be a fireproof cable .

According to the fireproof cable having the configuration of (1) above, the fireproof tape is spirally wound so as to cover the outer periphery of the conductor core wire while overlapping its edges, and the fireproof tape covers the outer periphery of the conductor core wire. A fireproof layer is formed on the outer periphery of the conductor core wire by at least one of the provisions along the longitudinal direction of the conductor core wire. That is, the refractory cable may have either one of the former refractory layer and the latter refractory layer, or may have both. As a result, fire resistance is exhibited. Further, a refractory holding thread is wound around the outer periphery of the refractory layer. Therefore, even if the refractory cable is bent, peeling of the refractory layer is suppressed by the holding thread, and a gap due to displacement or bending of the refractory tape at the overlapping portion of the refractory tape is unlikely to occur. As a result, the conductor core wire is unlikely to be exposed to the outside through the gap, so that the fire resistance performance of the fireproof cable is unlikely to deteriorate. In addition, since it is difficult for the conductive substance to enter the gap, the insulating property of the conductor core wire is unlikely to deteriorate.

Further, the holding thread itself is made of a material having fire resistance. Therefore, as compared with the case where the holding thread having no fire resistance is adopted, the above-mentioned effect of suppressing the generation of the gap by the holding thread can be exhibited for a longer time in the event of a fire. Therefore, the fire resistance performance of the fire resistance cable can be improved in this respect as well.
Further, the refractory material layer constituting the refractory tape is composed of a thin mica layer. Therefore, by utilizing the excellent fire resistance and insulation of mica, the fire resistance of the fireproof cable and the insulation of the conductor core wire can be appropriately maintained.

Therefore, the refractory cable having this configuration can properly maintain the fire resistance performance even if it is bent, and can properly maintain the insulation property of the conductor core wire.

According to the refractory cable having the configuration of (2) above, the holding yarn is wound around the refractory layer by a so-called cross-binding method consisting of an S-wound yarn and a Z-wound yarn. Therefore, as compared with the case where the holding yarn is wound around the fireproof layer only with the S winding yarn and the Z winding yarn only, a gap is less likely to be generated in the overlapping portion of the refractory tape when the refractory cable is bent.

According to the present invention, it is possible to provide a fireproof cable capable of appropriately maintaining fireproof performance even when bent.

The present invention has been briefly described above. Further, the details of the present invention will be further clarified by reading through the embodiments described below (hereinafter referred to as "embodiments") with reference to the accompanying drawings.

1A and 1B are views showing a configuration of a refractory cable according to an embodiment of the present invention, FIG. 1A is a schematic cross-sectional view of the refractory cable, and FIG. 1B is a schematic cross-sectional view of the refractory tape. FIG. 2 is a schematic view showing a state in which a holding thread is wound around the outer periphery of a refractory tape wound (overlap wound) around a conductor core wire. FIG. 3 is a schematic cross-sectional view of the conductor core wire and the refractory tape, and is a schematic view showing a state in which a gap is generated in the overlapping portion of the refractory tape because the holding thread is not wound. FIG. 4 is a schematic cross-sectional view of the conductor core wire and the refractory tape, and is a schematic view showing how the holding thread is wound so that no gap is formed in the overlapping portion of the refractory tape. FIG. 5 is a schematic cross-sectional view of the refractory tape according to the modified example. FIG. 6 is a schematic view of an insulated wire core according to another modified example. 7A and 7B are views showing an example of a conventional refractory cable, FIG. 7A is a schematic perspective view showing a configuration of the conventional cable, FIG. 7B is a schematic cross-sectional view of the conventional cable, and FIG. 7C is a diagram. Is a schematic cross-sectional view of a fireproof tape conventionally used for a cable.

Hereinafter, the refractory cable 100 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 4.

<Structure>
As shown in FIG. 1A, the refractory cable 100 includes a plurality of (two) insulated cores 110, a tubular sheath 120 for bundling the plurality of insulated cores 110, and an insulated core 110 and a sheath 120. An inclusion 130 interposed between the inclusions 130 and a presser foot winding tape 140 wound around the outer periphery of the inclusion 130 are provided. When the fireproof cable 100 includes only one insulated wire core 110 (that is, in the case of a single core), the inclusion 130 is unnecessary, and the sheath 120 is directly provided on the outer periphery of the insulated wire core 110. ..

Each of the insulating wire cores 110 covers the conductor core wire 111, the fireproof tape 112 covering the conductor core wire 111, the holding thread 113 wound around the outer periphery of the fireproof tape 112, and the fireproof tape 112 around which the holding thread 113 is wound. It has a body layer 114 and.

As shown in FIG. 1B, the refractory tape 112 has a mica layer 112a formed from a thin mica layer and a resin layer 112b. The resin layer 112b may contain powdered mica (powdered mica).

The mica layer 112a includes, for example, peeled mica obtained by peeling mica ore into a thin layer (scaly shape), mica paper obtained by extracting powdered mica obtained by crushing mica ore into a thin layer, or an adhesive or the like on mica paper. It can be formed from aggregated mica that has been impregnated and then heat compressed. In other words, the mica layer 112a may be composed of a thin layer (scaly) mica itself, or may be a mixture of a thin layer of mica and a resin, an adhesive, or the like.

The resin layer 112b can be formed from, for example, polyethylene. Further, from the viewpoint of further improving the fire resistance, powdered mica (powdered mica) may be contained in the resin layer 112b. In this case, the resin layer 112b can be formed from, for example, a mixed resin containing powdered mica obtained by crushing mica ore in polyethylene. The size of the powdered mica 112c contained in the resin layer 112b is preferably smaller than the size of the mica constituting the mica layer 112a.

As shown in FIG. 2, the refractory tape 112 is overlaid and wound around the outer periphery of the conductor core wire 111. Specifically, the refractory tape 112 is spirally wound around the outer periphery of the conductor core wire 111 so as to circulate in the S twist direction while maintaining a predetermined stacking allowance A (see also FIG. 3). As a result, the outer circumference of the conductor core wire 111 is covered with a refractory layer made of the refractory tape 112. The distance in the longitudinal direction that the refractory tape 112 travels when it makes one rotation is called "winding pitch length P1" (see FIG. 2).

The holding thread 113 is made of a material having fire resistance. Examples of such a holding yarn 113 include a glass yarn (registered trademark) manufactured by Unitika Ltd. As shown in FIG. 2, the holding thread 113 is directly wound around the outer circumference of the refractory tape 112 (refractory layer). Specifically, the holding yarn 113 is spirally wound around the outer circumference of the refractory tape 112 in the S twist direction so as to be spirally wound around the outer circumference of the refractory tape 112 in the Z twist direction. It is composed of a Z-wound 113z wound spirally. That is, the holding yarn 113 is wound around the fireproof tape 112 (fireproof layer) by a so-called cross-binding method using the S winding yarn 113s, the Z winding yarn, and 113z.

The number of each of the S winding yarn 113s and the Z winding yarn 113z is not particularly limited, but is preferably two or more. For example, as the number of the S winding yarn 113s and the Z winding yarn 113z, two, three or four yarns can be mentioned from the viewpoint of production efficiency and the like. In this example, two S-winding yarns 113s and two Z-winding yarns 113z are used. The S-wound 113s and the Z-wound 113z may be different types of yarns or the same type of yarns.

The longitudinal distance traveled when the S winding yarn 113s makes one rotation is called "winding pitch length P2s", and the longitudinal distance traveled when the Z winding yarn 113z makes one rotation is called "winding pitch length P2z". The winding pitch lengths P2s and P2z are preferably set to 3 to 8 mm in consideration of fire resistance and flexibility. It is preferable that the winding pitch length P2s and the winding pitch length P2z are equal to each other. Further, the winding pitch length P1 is preferably set to, for example, about 1 to 2 times the winding pitch lengths P2s and P2z.

With reference to FIG. 1 again, inclusions 130 can be formed, for example, from polypropylene. The inclusions 130 cover the insulator layer 114 of the insulating wire core 110. The inclusion 130 may contain powdered mica (powdered mica). When powdered mica (powdered mica) is contained, the inclusion 130 can be formed from, for example, a mixed resin containing powdered mica obtained by crushing mica ore in polypropylene.

<Fire resistance>
The refractory cable 100 covers the conductor core wire 111 with the mica layer 112a of the refractory tape 112 as the refractory layer. Since mica contained in the mica layer 112a is excellent in flame retardancy, it takes a considerable amount of time for the mica layer 112a to be burnt down even in a high temperature environment at the time of fire. Therefore, even if the refractory cable 100 is exposed to a flame at the time of a fire, the conductor core wire 111 can be prevented from being exposed to the outside until the mica layer 112a is burnt down.

Hereinafter, as a preparation for explaining the action / effect of winding the holding thread 113 around the outer periphery of the fireproof tape 112 overlaid on the conductor core wire 111 in the fireproof cable 100, first, as shown in FIG. 3, the conductor core wire A case where the holding thread is not wound around the outer periphery of the refractory tape 112 overlaid on the 111 will be described.

As shown in FIG. 3, when the holding thread is not wound around the outer periphery of the refractory tape 112, if the refractory cable is bent during manufacturing or wiring of the refractory cable, the refractory tape 112 may be displaced or bent. Therefore, a gap B may occur in the overlapping portion (the portion corresponding to the stacking allowance A) of the refractory tape 112. If such a gap B exists, the conductor core wire 111 is exposed to the outside through the gap B, which may reduce the fire resistance performance of the fireproof cable. In addition, if such a gap B is present, the conductive substance may enter the gap B, which may reduce the insulating property of the conductor core wire 111.

On the other hand, in the refractory cable 100, as shown in FIG. 4, the holding thread 113 is provided on the outer periphery of the refractory tape 112 at least a part of the outer peripheral portion of the overlapping portion (the portion corresponding to the stacking allowance A) of the refractory tape 112. It is wrapped so that it can be wrapped around. Therefore, even if the refractory cable 100 is bent, a gap due to displacement or bending of the refractory tape 112 is unlikely to occur in the overlapping portion of the refractory tape 112 (the portion corresponding to the stacking allowance A). As a result, the conductor core wire 111 is unlikely to be exposed to the outside through the gap, so that the fire resistance performance of the fireproof cable 100 is unlikely to deteriorate. In addition, since it is difficult for the conductive substance to enter the gap, the insulating property of the conductor core wire 111 is unlikely to deteriorate.

Even if the resin layer 112b of the refractory tape 112 is burnt down in a high temperature environment at the time of fire, the mica layer 112a may remain (exposed) on the conductor core wire 111. In this case, since the mica layer 112a itself has a certain degree of shape retention, the mica layer 112a does not reach the mica layer 112a unless an external force (for example, contact with a foreign substance from the outside, bending of the conductor core wire 111, etc.) is applied to the mica layer 112a. The state of being attached to the conductor core wire 111 can be maintained. That is, even if the resin layer 112b disappears, the fire resistance performance of the fireproof cable 100 is maintained as much as the mica layer 112a exists.

As described above, in the fireproof cable 100, the fireproof holding thread 113 is wound around the outer periphery of the fireproof layer made of the fireproof tape 112 formed on the outer periphery of the conductor core wire 111. Therefore, even if the refractory cable 100 is bent, a gap due to displacement or bending of the refractory tape 112 is unlikely to occur in the overlapping portion of the refractory tape 112 (see the stacking allowance A in FIG. 4). As a result, the conductor core wire is unlikely to be exposed to the outside through the gap, so that the fire resistance performance of the fireproof cable is unlikely to deteriorate. In addition, since it is difficult for the conductive substance to enter the gap, the insulating property of the conductor core wire is unlikely to deteriorate.

Further, the holding thread 113 itself is made of a material having fire resistance. Therefore, as compared with the case where the holding thread having no fire resistance is adopted, the above-mentioned effect of suppressing the generation of the gap by the holding thread 113 can be exhibited for a longer time in the event of a fire, and thus also in this respect. The fire resistance performance of the fire resistance cable 100 can be improved.

Further, the holding yarn 113 is wound around the refractory layer by a so-called cross-binding method using the S winding yarn 113s and the Z winding yarn 113z. Therefore, as compared with the case where the holding yarn is wound around the refractory layer only with the S winding yarn 113s and the Z winding yarn 113z, a gap is further generated in the overlapping portion of the refractory tape 112 when the refractory cable 100 is bent. It becomes difficult.

The present invention is not limited to each of the above embodiments, and various modifications can be adopted within the scope of the present invention. That is, the present invention is not limited to the above-described embodiment, and can be appropriately modified, improved, and the like. In addition, the material, shape, dimensions, number, arrangement location, etc. of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

For example, in the above embodiment, the refractory tape 112 is composed of two layers, a mica layer 112a and a resin layer 112b (see FIG. 1B). However, as shown in FIG. 5, the refractory cable of the present invention may be composed of three layers in which the refractory tape 112 is laminated so as to sandwich the mica layer 112a between a pair of resin layers 112b.

Further, in the above embodiment, mica is used as a heat resistant material in the mica layer 112a (refractory layer) of the refractory tape 112. However, the refractory cable of the present invention may be configured to use another material (eg, alumina powder) as the refractory material.

Further, in the above embodiment, the holding yarn 113 is wound around the refractory layer by a so-called cross-binding method using the S winding yarn 113s and the Z winding yarn 113z. However, the refractory cable of the present invention may be configured such that the holding yarn 113 is wound around the refractory layer only with the S winding yarn 113s and the Z winding yarn 113z only.

Further, in the above embodiment, the refractory tape 112 is spirally wound around the conductor core wire 111 (see FIG. 2). However, as shown in FIG. 6, the fireproof cable of the present invention may be configured such that the fireproof tape 112 is provided along the longitudinal direction of the conductor core wire 111 so as to cover the outer periphery of the conductor core wire 111. In addition, the refractory cable of the present invention may include both a refractory tape spirally wound as shown in FIG. 2 and a refractory tape provided along the longitudinal direction as shown in FIG. ..

Here, the features of the above-described embodiments of the refractory cable according to the present invention are briefly summarized and listed below (1) to (3), respectively.
(1)
A refractory cable (100) with one or more insulated cores (110).
The insulated wire core (110) is
The edge of the refractory tape (112) so that the conductor core wire (111) and the refractory tape (112) on which the resin layer (112b) and the refractory material layer (112a) are laminated cover the outer periphery of the conductor core wire (111). Along the longitudinal direction of the conductor core wire (111) so that the refractory layer (112 in FIG. 2) and the refractory tape (112) wound spirally while overlapping the conductor core wires (111) cover the outer periphery of the conductor core wire (111). It has at least one of the provided refractory layers (112 in FIG. 6) and a refractory holding thread (113) wound around the outer periphery of the refractory layer (112).
Fireproof cable.
(2)
In the fireproof cable described in (1) above,
The holding thread (113)
An S-wound (113s) wound around the outer circumference of the refractory tape (112) so as to circulate in the S-twist direction, and a Z-wound wound around the outer circumference of the refractory tape (112) so as to circulate in the Z-twist direction. Including thread (113z),
Fireproof cable.
(3)
In the fireproof cable described in (1) or (2) above,
The refractory material layer (112a) is composed of a thin layer of mica.
Fireproof cable.

100 Fireproof cable 110 Insulated core 111 Conductor core wire 112 Fireproof tape, Fireproof layer 112a Mica layer (Fireproof material layer)
112b Resin layer 113 Retaining thread 113s S winding thread 113z Z winding thread 120 sheath 130 inclusions

Claims (2)

A refractory cable with one or more insulated cores
The insulated wire core is
The refractory layer and the refractory tape are spirally wound so that the conductor core wire and the refractory tape in which the resin layer and the refractory material layer are laminated cover the outer periphery of the conductor core wire while overlapping the edges of the refractory tape. at least one refractory layer provided along the longitudinal direction of the conductor wire so as to cover the outer periphery of the conductor core, and a holding yarn refractory which is wound around the outer circumference of the refractory layer possess,
The refractory layer is composed of scaly mica itself.
The resin layer contains powdered mica, and the resin layer contains powdered mica.
The size of the powdery mica is smaller than the size of the scaly mica.
Fireproof cable. In the fireproof cable according to claim 1,
The holding thread
Includes an S-wound wound around the outer circumference of the refractory tape so as to circulate in the S-twist direction, and a Z-wound wound around the outer circumference of the refractory tape so as to circulate in the Z-twist direction.
Fireproof cable.

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